Tubular flexible grafts are currently a standard tool for repairing failures in the vascular system. During open surgical procedures such grafts are securely sewn onto the vessel in a manner that prevents detachment or leakage. Open surgical procedures however often carry substantial risk to the patient. In recent years a new technology has emerged which seeks to deliver grafts supported by stents through the use of catheter like devices introduced into the vascular system at a convenient location and then guided remotely to the site where the stent graft is implanted.
One of the more serious problems that the physicians using this technology have to cope with relates to the fact that the intraluminally implanted graft is less securely attached to the vessel wall and can therefore slip away from the intended location. Consequences of such slippage in the case of a large artery can be very serious. Various methods have been developed to counter this problem. Since trouble typically develops at the proximal attachment site, proximal ends of grafts have been equipped with hooks or uncovered stents, which after deployment extend beyond the treated area of the vessel to provide the necessary anchoring.